1.
A=⎝⎛10001/21/2⎠⎞,b=⎝⎛246⎠⎞
Then u is the orthogonal projection of b onto the subspace spanned by the column of A and it is given by the formula:
u=A(ATA)−1ATb
then:
ATb=(1001/201/2)⎝⎛246⎠⎞=(210/2)
ATA=(1001/201/2)⎝⎛10001/21/2⎠⎞=(1001)
(ATA)−1=(1001)
(ATA)−1ATb=(1001)(210/2)=(210/2)
u=⎝⎛10001/21/2⎠⎞(210/2)=⎝⎛255⎠⎞
2.
x2−4≥0⟹∣x∣≥2
then image of S:
f(x)≤2(−2)−1=−5 and
f(x)≥2⋅2−1=3
3.
for ker(T):
U+V=0
U+2U=0
so,
ker(T)=(0,0)
4.
by the rank-nullity theorem:
6=dim(Ker(T))+dim(Im(T))
So, dim range T= 6-dim(Ker(T))=6-2=4
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